Instead of the 32g? I think the 150 watt will be good for either, I don't have enough expireance with the small nano tanks to say wither the 24g will be good or not. I would say 32 gallons is better then 24....JMHO
Sounds okay to me, I've got the 70w sunpod on the 18, and its not cooking any of my zoas. Warning though, I'm getting evap like crazy, setting up an auto top off.